adam@0: task initialize = fn () => OpenidFfi.init
adam@1: 
adam@2: fun discover s =
adam@2:     r <- OpenidFfi.discover s;
adam@2:     return (Option.mp (fn r => {Endpoint = OpenidFfi.endpoint r,
adam@2:                                 LocalId = OpenidFfi.localId r}) r)
adam@3: 
adam@3: val createInputs =
adam@3:     is <- OpenidFfi.createInputs;
adam@3:     OpenidFfi.addInput is "openid.ns" "http://specs.openid.net/auth/2.0";
adam@3:     return is
adam@3: 
adam@3: table associations : { Endpoint : string, Secret : string, Expires : time }
adam@3:   PRIMARY KEY Endpoint
adam@3: 
adam@3: task periodic 0 = fn () => dml (DELETE FROM associations WHERE Expires < CURRENT_TIMESTAMP)
adam@3: 
adam@3: datatype association = Handle of string | Error of string
adam@3: 
adam@3: fun association url =
adam@3:     secret <- oneOrNoRowsE1 (SELECT (associations.Secret)
adam@3:                              FROM associations
adam@3:                              WHERE associations.Endpoint = {[url]});
adam@3:     case secret of
adam@3:         Some v => return (Handle v)
adam@3:       | None =>
adam@3:         is <- createInputs;
adam@3:         OpenidFfi.addInput is "openid.mode" "associate";
adam@3:         OpenidFfi.addInput is "openid.assoc_type" "HMAC-SHA256";
adam@3:         OpenidFfi.addInput is "openid.session_type" "no-encryption";
adam@3:         os <- OpenidFfi.indirect url is;
adam@3:         case OpenidFfi.getOutput os "error" of
adam@3:             Some v => return (Error v)
adam@3:           | None =>
adam@3:             case (OpenidFfi.getOutput os "assoc_handle", OpenidFfi.getOutput os "expires_in") of
adam@3:                 (Some handle, Some expires) =>
adam@3:                 (case read expires of
adam@3:                      None => return (Error "Invalid 'expires_in' field")
adam@3:                    | Some expires =>
adam@3:                      tm <- now;
adam@3:                      dml (INSERT INTO associations (Endpoint, Secret, Expires)
adam@3:                           VALUES ({[url]}, {[handle]}, {[addSeconds tm expires]}));
adam@3:                      return (Handle handle))
adam@3:               | _ => return (Error "Missing fields in response from OP")